This application is based on and incorporates herein by reference Japanese Patent Application No. 2001-88591 filed on Mar. 26, 2001.
The present invention relates to an onboard displaying device for a vehicle including a head-up display.
One type of head-up display for a vehicle is disclosed in JP-A-6-130317. It forms virtual images of information, including traveling speed and warning patterns of a vehicle, transmitted from a liquid crystal display (LCD) in front of a front windshield. Another type of head-up display is disclosed in U.S. Pat. No. 5,781,243. A night-vision camera captures scenes ahead of a vehicle and virtual images of the scenes are formed in front of the front windshield as a vision aid.
When displaying different kinds of information by a single head-up display as in those displaying devices, displayed images may be mixed up and visibility of a driver decreases. Switching information to be displayed based on road conditions is one way to counter this problem. As an example for improving visibility of a driver, a head-up display which changes colors of the entire display surface of the LCD based on kinds of information is disclosed in JP-A-6-130383. However, the sizes of the LCD and a light source of this head-up display become large. As a result, the installability decreases while the cost increases.
The present invention therefore has an objective to provide a displaying device for a vehicle to display different kinds of information by a single LCD panel with a compact light source, while maintaining good visibility.
Information for driving generally falls into two categories. One is a kind of information a driver may prefer to see in large images because it is necessary for driving. The other is a kind of information the driver may not need to see in large images because it is supplemental information for driving. These kinds of information are defined as high priority information and low priority information, respectively.
A displaying device for a vehicle of the present invention includes an LCD panel and a light source. The LCD panel displays the low priority information on a part of a display surface. It also displays the high priority information on a wider display surface which includes the narrow display surface.
Moreover, two types of light emitting devices, one for a large area and the other for a small area, are used for the light source. The light emitting device for a large area has higher directivity than the one for a small area. Therefore, the high priority information and the low priority information are selectively displayed with a light source which is still compact in size.